Isolation, Characterization and Identification of Salt Tolerant Nitrogen Fixing Bacteria
The present investigation deals with the isolation and characterization of nitrogen fixing bacteria (NFB) such as Azotobacter sp. and Azospirillum sp. from paddy field rhizosphere of Damietta governorate, Egypt. 12 Azotobacter spp. and 12 Azospirillum spp. were identified based on morphological and physiological characteristics. Nitrogen fixation capacity was determined. All isolates were tested for salt tolerant. the highest salt tolerant of Azotobacter spp. were S2-8, S3-3, S1-3, S3-2. While Azospirillum spp. were S2-11, S1-1, S5-1, S3-6. Nitrogenase activity assay of the highest salt tolerant isolates was in the case of Azotobacter sp. (S2-8) and in case of Azospirillum sp. was S2-11. Molecular identification shown these isolates ware Azotobacter chroococcum and Azospirillm brasilense.